* <del>[http://www.mit.edu/~vona/Visolate/Visolate-info.html Visolate]: To create the isolation paths. We use an unreleased version, that is scriptable.</del>

+

* Meanwhile, [http://sourceforge.net/projects/pcb2gcode/ pcb2gcode] was adopted and is used.

* [http://code.google.com/p/grecode/ grecode] To mirror the board for second side. (Grecode was created especially for metaboard.sh by --[[Benutzer:Bkubicek|Bkubicek]] 09:55, 26. Jul. 2010 (CEST))

* [http://code.google.com/p/grecode/ grecode] To mirror the board for second side. (Grecode was created especially for metaboard.sh by --[[Benutzer:Bkubicek|Bkubicek]] 09:55, 26. Jul. 2010 (CEST))

−

While these are called, a couple of windows will pop up and hopefully disappear again.

+

While these are called, <del>a couple of windows will pop up and hopefully disappear again.</del> only shell output will be produced. you will get some debug images also in the current directory.

−

Possible issues:

−

* Eagle sometimes stays on top: just close the opened .brd, and load your .brd again using the menu. If have no clue why this happens.

−

* It might be necessary to have a parent project file in the same directory?

−

=== Usage ===

+

+

+

== Usage ==

The workflow splits into the following points:

The workflow splits into the following points:

* Preperation: create an eagle brd file, copy it

* Preperation: create an eagle brd file, copy it

−

* Metaboard.sh: create the gcode files for the geilomat

+

* Metaboard*.sh: create the gcode files for the geilomat

−

* Setup: mount the board in the geilomat, insert a suitable mill head.

+

** For the most current worflow use metaboard3.sh . It will require a 0.6 mm mill head, which is the best, as small IC holes are possible, and the tool length is so small that little sidewards forces are created. Hence, mill speed is larger than for 0.8mm tools.

−

* EMC-setup: home the machine, "touch off"/set coordinate system so milling will be on the actual board

+

* Setup:

−

* Bottom layer:

+

** mount the board in the geilomat using double sided sticky tape.

−

** drilling and cutting

+

** On the flat milled wood area.

−

** Isolation-milling

+

**Which should be de-dusted first.

+

**Double sided tape should not overlap, as this creates 0.1mm height difference.

+

**Insert a suitable tool. Either a sharp Gravierstichel .

+

[[Datei:gravierstichel.jpg]]

+

* EMC-setup: home the machine "home all", "touch off"/set coordinate system so milling will be on the actual board

+

+

Bottom layer:

+

** Isolation-milling: use the *back.ngc file created by metaboard3.sh

+

** drilling: use the *drill*.ngc file created by metaboard3.sh

+

** and cutting: use the *outline*.ngc file created by metaboard3.sh.

+

For single sided boards, the process stops here.

For single sided boards, the process stops here.

−

* Flipping the board, mounting it.

+

Double sided boards are more sophisticated:

+

* Flipp the board, mounting it in any usefull position.

* Top layer:

* Top layer:

−

** Loading the top layer debugging file.

+

* note down two drill hole coordinates from the drill file, in mm units.

−

** Aligning: Rotate and shift the top layers using grecode, so that the new gocde matches the mounted board.

+

* navigate using the joypad to the holes location on the flipped mounted PCB. Write down the coordinates of the special holes.

−

** Isolate the top.

+

* call "grecode -align x1 y1 x2 y2 X1 Y1 X2 Y2 *front*.ngc > tmp.ngc" to rotate and shift. Maybe you have to change the signs of the x1 and x2, depending of the pcb2gcode version you use.

If all goes well, you will obtain a lot of *.ngc files, that contain [[http://en.wikipedia.org/wiki/G-code Gcode]] for the CNC process. Also, a tmp directory will be created, where there are even more files.

+

−

The files in the original directoy are:

+

−

* xxx_top.ngc: The top layer isloation paths.

+

−

* xxx_bottom.ngc: The bottom layer isloation paths.

+

−

* xxx_drillcuttop.ngc: The top layer drilling and cutting.

+

−

* xxx_drillcutbottom.ngc: The bottom layer drilling and cutting.

+

−

* xxx_debug.ngc: A file so you can view the content of all the other files at once, to check for errors, or measure coordinates..

+

−

+

−

===Preperation===

+

−

+

−

Then you start [[linuxcnc.org/ EMC]] on the computer next to the geilomat. You load the xxx_debug.ngc file and look at it really intense to see weather it is correct.

+

−

+

−

Then you press the home-all bottom, and the mill will move to its home position on the close left corner in front of you.

+

−

+

−

Mount the board using the thin double sided tape and stick it to the flat-milled piece of wood.

+

−

+

−

You want to insert a 0.8 mm mill-head in the Kress (a drill might break in the the sidewards cutting movement).

+

−

Then you move to one location just above the mounted PCB, and set the working coordinate system using "touch off" in X and Y. For the Z, you move next to the PCB, and go tiny bit deeper than the lower board edge, and touch off at the lowest z-coordinate value, which should be -2.5 mm. For security, move up so that the mill can move freely thereafter.

+

−

+

−

===Bottom Layer===

+

−

+

−

Load the xxx_bottomdrillcut.ngc file.

+

−

+

−

For the drilling, set the Kress to speed "5".

+

−

+

−

Close the geilomat-latch. Turn the spindle on in EMC so that the Kress rotates. Press the play button and watch out for problems. Stop with the Stop button, or with F1. After an emergency off with F1, you maybe have to reposition the machine. Try not to be overwhelmed by all the noise and awesomeness.

+

−

+

−

After the drilling and cutting has finished, move the mill so you can change the mill-head to a 0.1mm-0.3mm 30°-45° "Gravierstichel".Then, right next to the side of the board, or onto an hole, and touch off Z so that zero is ~0.3mm underneath the surface. Check the flatness of the board, and if there are problems, move deeper into the board.

+

−

+

−

Load the xxx_bottom.ngc file. Isolate the bottom.

+

−

+

−

===Top layer===

+

−

+

−

Then remove the board, remove the sticky tape, and clean the surface a bit. Mount a new batch of tape to the milled surface, and glue it onto the wood so that you see the to-be top layer.

+

−

+

−

load the xxx_debug file.

+

−

Define two positions on the board that you identify both on the mounted board and the in the software. Only drill holes or cut-corners on the flipped top surface are suitable !

+

−

Read the coordinates of this points in EMC by clicking at the line and reading the X-Y coordiates in the gcode-text-view. Write them down.

+

−

+

−

+

−

Move the mill to the same locations, and write down the coordinates displayed in the 3d-window.

If you change the diameter of your vias to 0.8, you can use the 0.6 inner diameter "Kupferhohlnieten". if you have a double side-connected pin of you 0.7 mm you might want to use a 1mm hole, to use the larger "hohlnieten", where you can then insert a 0.7mm pin.

−

* Then start Visolate, load the gerber file, make if full screen. press Fit. Fix Topology. Make toolpaths. Output file as "isolate_boardname.ngc"

+

Pins of through-hole mounted devices also do not form automatic top-bottom connections. This especially frustrating with the eagle autorouter, because I found no way of turning this off. Sometimes you can compensate by soldering also on the top side of the part, but very often there is really no space for that. Best thing is to manually overwork the board in eagle.

−

* Then comes the joining of the three ngc files: Create a new ngc file starting with

+

[[Datei:goodpad.png|center|thumb|400px|How to make your solder easier.]]

−

M8 ; turn on spindle ; adjust to your mill

+

−

F450

+

−

G90

+

−

G21

+

−

G0 Z2.54 ; move up to 0.1 inch above

+

−

G0 X-0.24 Y-0.24 ;change this to align the drill holes with the the isolation path

+

−

G20

+

−

;; end head

+

−

then add the content of isolate_boardname.ngc without the m5 m3 tail. The isolation has relative coordinates, so we have to set a proper starting location via the previous head. Also, moving to the assumed Z=0 position would already mill the board, so we have to change the first Z move.

+

−

comment out the first move to Z-0.01

+

−

it could look something like this

+

−

G20

+

−

G17 G40 G49 G80

+

−

G91

+

−

G1 Z0.1

+

−

G0 X0.10814 Y0.28534

+

−

;G1 Z-0.1 ;; uncommented t

+

−

G1 X0.00392 Y0

+

−

;; end isolate

+

−

insert a commented line with an end program.

+

−

; G0 Z20 M2 ; program end to manual tool-change to drill

+

−

after the isolation we will insert the content of drill_boardname.ngc

+

−

adjust the variables posdown to -2.1 posup to 1, feedown to 100,feedup to 200

+

−

after the cutting, create some blank lines and insert a section of cut_boardname.ngc, namely the part between (Start cutting wires) and (finished). This movements cut out the pcb from the surrounding.

+

−

Maybe you have to invert all Y coordinates because of the mirroring

+

+

=== Routing ===

+

While the eagle autorouter tries to bundle wires closely together, for voronoi shaped pcbs, this is not so optimal.

+

You can still use the autorouter, however I would recommend it only on the bottom layer. I use a 12.5 mil routing grid usually, and * for bottom N/A for top.

+

Then I move the wires around, so that the sidewards distance is maximized. This is done by having arbitrary diagonals, and successively moving outer wires further outside.

−

The complete file then should have some head, the isolation, the drilling and the cutting.

+

[[Datei:brdgoodpad.png|thumb|center|800px| Example of good (not really good, but sufficient) and bad wire placement". It is not a very good example, I will try to produce if there is time]]

−

* Open this ngc file in axis, and adjust the relative position of the drills to the isolation by the G0 X Y in the head, saving and reloading in axis.

+

=== Mounting Holes ===

+

Currently PCB2Gcode does not respect mounting holes, meaning that it would grow the wires possibly in a way that two different signals could be short-circuited by the screw. To prevent this, place a bottom wire-arc around the screw. Then it gets it's own "pad".

−

* Check if whether the board is in a right orientation or if it needs to be mirrored. This can be achieved by my gcode -filters: http://www.linuxcnc.org/images/fbfiles/files/grecode.zip , see also this [http://www.linuxcnc.org/component/option,com_kunena/Itemid,20/func,view/catid,38/id,2288/limit,6/limitstart,12/lang,english/#2448 forum post]

+

=== Isolation Distances ===

+

If you happen to work with larger voltages, you need isolated gaps on the PCB. I would do that by drawing a filled polygon on the bottom layer, or a group of overlapping or connected wires, as if the isolation were a wire.

+

After the milling, I would use a sharp knife to lift the copper from the board at a corner, and peel it off. If you know the trick, it works quite well.

−

* after all is good, remove the commend right before the drilling, to have the the program stop there. Reload in axis. Insert a 30 Degree 0.1 or 0.2 mm "Gravierstichel", home the machine, touch off at a suitable location, and start the program.

+

[[Datei:peeledpcb.png|thumb|center|600px|A peeled off PCB. In this case, it is not an actual isolation distance, but just for the screws. You see here that I needed to peel off multiple areas. If I had connected the individual regions with overlapping wires, I could have saved some time.]]

−

* If the isolation is not deep enough, touch off z in lower height, and restart.

+

−

Then Change to a 0.6 mm drill with a 3.12mm 1/8 inch holing diameter, touch of Z again, and re-insert the comment right before the drilling.

+

−

* Reload in Axis, scroll to the line right before the drilling, right click->run from here.

* if you really want things to be perfect, you could locate the most outwards line in the isolation, and move them deeper Z-0.1 ->Z-0.12 and the following relative up-movent as well Z0.1 ->Z0.12. By that, there will be no copper close to the cutting locations.

For the isolation, there is the normal approach, where all contours of copper areas are milled.
However much faster results can be obtained by milling the minimal path necessary to create the PCB-topology.

grecode To mirror the board for second side. (Grecode was created especially for metaboard.sh by --Bkubicek 09:55, 26. Jul. 2010 (CEST))

While these are called, a couple of windows will pop up and hopefully disappear again. only shell output will be produced. you will get some debug images also in the current directory.

Usage

The workflow splits into the following points:

Preperation: create an eagle brd file, copy it

Metaboard*.sh: create the gcode files for the geilomat

For the most current worflow use metaboard3.sh . It will require a 0.6 mm mill head, which is the best, as small IC holes are possible, and the tool length is so small that little sidewards forces are created. Hence, mill speed is larger than for 0.8mm tools.

Setup:

mount the board in the geilomat using double sided sticky tape.

On the flat milled wood area.

Which should be de-dusted first.

Double sided tape should not overlap, as this creates 0.1mm height difference.

Insert a suitable tool. Either a sharp Gravierstichel .

EMC-setup: home the machine "home all", "touch off"/set coordinate system so milling will be on the actual board

Bottom layer:

Isolation-milling: use the *back.ngc file created by metaboard3.sh

drilling: use the *drill*.ngc file created by metaboard3.sh

and cutting: use the *outline*.ngc file created by metaboard3.sh.

For single sided boards, the process stops here.
Double sided boards are more sophisticated:

Flipp the board, mounting it in any usefull position.

Top layer:

note down two drill hole coordinates from the drill file, in mm units.

navigate using the joypad to the holes location on the flipped mounted PCB. Write down the coordinates of the special holes.

call "grecode -align x1 y1 x2 y2 X1 Y1 X2 Y2 *front*.ngc > tmp.ngc" to rotate and shift. Maybe you have to change the signs of the x1 and x2, depending of the pcb2gcode version you use.

Loading the tmp.ngc file just created

check if the gcode is now aligned with the pcb.

Isolate the top.

Removing the boards works best by using a twist motion around the z-axis. A brush should be nearby to clean the grooves.

Hints

VIAS

larger "Kupferhohlnieten"

smaller "Kupferhohlnieten"

Milled vias form no automatic connection between top and bottom. You can solder them using a small copper wire. Or the magical Kupferhohlnieten.

If you change the diameter of your vias to 0.8, you can use the 0.6 inner diameter "Kupferhohlnieten". if you have a double side-connected pin of you 0.7 mm you might want to use a 1mm hole, to use the larger "hohlnieten", where you can then insert a 0.7mm pin.

Pins of through-hole mounted devices also do not form automatic top-bottom connections. This especially frustrating with the eagle autorouter, because I found no way of turning this off. Sometimes you can compensate by soldering also on the top side of the part, but very often there is really no space for that. Best thing is to manually overwork the board in eagle.

How to make your solder easier.

Routing

While the eagle autorouter tries to bundle wires closely together, for voronoi shaped pcbs, this is not so optimal.
You can still use the autorouter, however I would recommend it only on the bottom layer. I use a 12.5 mil routing grid usually, and * for bottom N/A for top.
Then I move the wires around, so that the sidewards distance is maximized. This is done by having arbitrary diagonals, and successively moving outer wires further outside.

Example of good (not really good, but sufficient) and bad wire placement". It is not a very good example, I will try to produce if there is time

Mounting Holes

Currently PCB2Gcode does not respect mounting holes, meaning that it would grow the wires possibly in a way that two different signals could be short-circuited by the screw. To prevent this, place a bottom wire-arc around the screw. Then it gets it's own "pad".

Isolation Distances

If you happen to work with larger voltages, you need isolated gaps on the PCB. I would do that by drawing a filled polygon on the bottom layer, or a group of overlapping or connected wires, as if the isolation were a wire.
After the milling, I would use a sharp knife to lift the copper from the board at a corner, and peel it off. If you know the trick, it works quite well.

A peeled off PCB. In this case, it is not an actual isolation distance, but just for the screws. You see here that I needed to peel off multiple areas. If I had connected the individual regions with overlapping wires, I could have saved some time.